Compressor unloader mechanism



March 20, 1928.

F. A.v MULLER ET AL COMPRESSOR UNLOADER MECHANISM Filed July 7. 1927 S T. m V mm Mz BY ATTORNEYS a safety valve S.

Patented hilera. 2Q, ld,

hlllllll FREDERICK A. MULLER, F RCTrIl/QND HELL, AND" LORENTZ L. IBASBERG, OF BROOK- LYN, NEX/V YORK, SSC-llG-S TG JANET CLEARY, TRADING "UNDER NAME QF AEIEBIOAN A1B COMPRESSOR VQRKES,

on BROOKLYN, NEW YORK.

COMBESSGR 'UNLOADEBJ MECHANISIVI.

application mea my 7, 1927. serial No. 204,113.

This invention relates to compressors and more particularly to electric compressor unloader mechanisms adapted to be automatically controlled by the air pressure in the receiver.

. One object ot our invention is to provide a combination oit mechanisms which will simultaneously control and relieve the load on electric motor driven compressors more particularly at the period ot starting and stopping operations. v

Another object is to provide mechanisms which coact with the motor drivenv compressor to assure the unloading of the. compressor during the period of acceleration.

A practical embodiment et our invention is represented in the accompanying drawing, in which i l Fig. 1 illustrates the relation o certain ot the parts diagraminatically and other ot the mechanisms partly in side elevation and partly in cross section, and

Fig. 2 represents a vertical section, on an enlarged scale, of the device 1for control V ling the compressed air from the receiver.

TheV compressor is denoted by 1 and may be ot any well known or approved Vvype hat# ing an air inlet pipe 2 and an outlet pipe 3. The air receiver fl, also ot the usual well known construction, has an inlet pipe 5, a valved outlet pipe 6, a pressure gauge-7, and interposed between the outlet pipe 3 et the compressor and the inlet pipe 5 of the receiver we located a check 7alve which comprises a body member 10 having an inlet 11, which connects with the outlet-pipe 3, and a cover 12 provided with an outlet 13 which is coupled with the inlet pipe 5 oi the receiver A stop cock is disposed in the body member` 10, to openv communication with the external atmosphere at the will ot the operator. v

The body member 10 is provided .with a valve seat 14k having` passages 15, therethrough. A plate valve 17 is arranged to be moved away from its seat 14: by the pressure of the air through the compressor outlet pipe 3, and moved toward its seat by the air pressure in the pipe 5 of the receiver l.

The body member 10 of the check valve is provided betweenthe inlet 11 and the valve seat la with an outlet pipe 18 which con- 23, which is interposed between an adjust'- -ing screwv 24, threaded in they casingA 19, and

the plunger valve' 20. A lock nut 25 serves to securethe adjusting screw 24 against unintentional displacement. j'lhe plunger valve isfalso provided with a downwardly eX- tending stem 26 which passes through a tubular passage 27 Vin the casing 19, and its lower end is attached to a diaphragm28. The4 peripheral edge of this diaphragm is secured between armember 29 and its cover 30, -which member and cover arey constructed with av timing chamber 3l below the diaphragm and a smaller chamber 32 above the diaphragm. The member andV its cover are held in position on the casing 19 by the cover having ayscrew threaded engagement with a threaded nipple 33 extending downwardly from the casing`19. The outlet pipe 18 is arranged to communicate with the external atmosphere througha .passage 3l in the casing 19, which passage is opened and closed by the plunger valve 20.

i The air in the receiver is allowed to pass through a valve 35 to apip'e 36 of relatively small diameter to a control device 37, thence 'through a pipe 38 ot similar diameter 'con-I nec-ted with Athe timing chamber 31 of the i;i'ieniber 29. n

The control Adevice 37 is provided with aninlet port 39, a discharge port l0 and an Xhaust port (l1, of which the inlet and eX- haust ports aredisposed in vertical alinement, while thedischarge port 40 is located substantially at right angles to the inlet and exhaust ports and midway therebetween.

A spring actuatedV valve l2 having a depending stem is arranged to open and close a passage 43 interposed between the inlet and discharge ports. A passage 44 islocated between the discharge and exhaust ports and is openedand closed by means of a needle valve 115, which is arranged to eX- tend a distance below, vand be reciprocated j in the exhaust port Ll1 the purpose o which will be hereinafter referred to. The needle valve a5 is provided with a stem 46 which extends upwardly through the passage 44e starter 63.

li U

into position to engage the depending stem oi' the valve 42 and a spring pressed plunger 46:1which is disposed in position to be actuated by a pressure snap switch of any well Vknown or approved construction. In the present form of switch mechanism we have shown a rocking lever 47 pivoted at 48 to a housing 49, one end of which lever 47 engages the plunger 46",: while the other end controls the movement of a Contact switch 50. A diaphragm 51 is mounted'in a chamber 520i the housing 49, and has a pin 53 extending through'the housing in position to `engage one arm` 54 of -a bell'erank lever 55 pivoted at 56 on the housing The other arm 57, of the bell crank lever 55, is connected to the lever 47, by a vibrating link 58. The diaphragm 5l is held in its normal position and against the pressure of air inthe receiver 4, byV means of a spring 59, one end lof whichis lconnected to the arm 57, while the other end is adjustably attached to the vhousing 49. The tension of the'spring 59 is adjusted'to regulate the movement of the diaphragm .5l through its pin 53 'andbell crank lever 55.- A motor 60 drives the compressor through the usual pulley and belt connections, and receives its electric power from main electric power lines 6l-'462.

An'au'tomatic starter 63 is connected with the motor 6() by wires (i4-,435 and maybe throw-n into and out ofdirect connection with the main lines 61-62 by means of a double pole switch 66. Wires 67-68 `are also Aconnected with the double pole switch 66 and the toggle switch 50, which wires lead from the switch 50 to the automatic In operation :-Assuming that the pressure of' airin thereservoir hasreached the pointabove vwhichv the tension vspring 59 is set, the `diaphragm 5l will be pressed to the left therebycausingthe' pin 53`to actuate the bell crank lever which lin turn transmits its motion to the rocking lever 47 throughrthe vibrating link 53. rlhe roeking of the lever' 47-inoves the toggle of the switch 50 and breaks the electrical contact ot the wires 67-'68 with the main line wires (ll-62 thereby stopping the motor 60. Simultaneously with the movement oi the switch V50,*the lever 47 actuates the needle valve 45, which raises the valve 42 from its seat, against the air pressure and the tension of itsspring, by means of the stem 46 and permits the air in the pipe '36 to pass through the passage43 to the discharge port y 40, thence through the pipe 33 .to the timing chamber 3l.

As the valve 42 is raised 'from its seat the needle valve 45` will be brought to itsy seat and close the passage 46. Any further movement of the lever 47 will be absorbed by the spring actuated plunger 4G* housed. in the body of the needle valve 45. When the compressed air enters the chamber 3l it will lift they diaphragm 28,

which in turn raises the plunger valve 2O from its seat 21, against the tension of its spring 2", and allows the'entrapped air between the check valve 10 and the compressor to pass through the passage 34 to external atmosphere, thus releasing the pressure in the compressor.

When the pressure vof the air in the receiverl has reached the point equal' to or below the tension of the spring 59 the air pressure in contact with the diaphragm 51 will also be reduced, and the 'spring 59 will causethe bell crank lever 55 to resume its normalv position. frs the bell crank lever`55 returns to its normal position 1t rocks the lever 47, which moves the contact switch 50 to close the circuit of the main lines (3l-52 and wires 67-63, so vthat the automatic starter 63 will be actuated and theinotor 69 and compressor again set in motion. Y

Simultaneously with the movement of the switch 50 the lever 47 released its pressure on the needle valve 45 vso that the valve moved away from its seat on the passage 44 and allowed. the spring actuated valve 42 to close the passagev 43. As `the passage 43 kis closed the passage 44 will be opened'- ing up air pressure in the pipe 3 and check valve so that as soon as the chamber 3l is exhausted the plunger valve 20 will close on its seat 2l` aided by the spring 23 and the com incssedfair which is being passed 'from the compressor to the pipe 3 and check valve. A :ttenthe plunger valve 20 is closed air will then be forced through the passages l5 past the plate valve i7 ot the check valve to the receiver 4.

Thus it will. be seen that the comn'essor is tree `to be brought to its maximum speed without av load, by the closing ofl the valve 2O upon its 2l., which closing is so timed that the compressor will discharge air through the passage 34 to external atmosphare until the air is exhausted from the chamber 3l and the diaphragm 28 tree to allow the valve 2O to close the passage 34.

.lf desired, the compressor l may be driven iminterruptedly and the air pressure in the receiver 4 relieved in the manner above de- .c i ed, except that thedouble pole switch ismovecl to the position shown lin dotted outline in Fig. l, in which position the elec-4 i et tric power from vthe main lines 61--62 is' passed to the wires Gil-65 directly through the automatic starter 63 to the motor 60, and breaking the Vcontact of the wires (iT-(S8 of the contact switch 50.

The timing of the atmospheric valve is dependent upon the amount ot' pressure applied to the spring 23 by the adjusting screw 2a and the area 'of the timing chamber 31,

together with the volume of air leakageV through the exhaust port 4l during' the period in which the compressor is being brought to its maximum speed.

To relieve the compressor at the initial starting the stop cock l0* is manipulated .to open the check valve to atmosphere, and closed when the compressor reaches its maximum speed.

it will be understood that various changes may be resorted to in the Jform, construction and arrangement of the several parts without departing from the spirit and scope of our invention; and hence, we do not intend to be limited to the details herein shown and described,'except as they may be included in the claims.

lWhat we claim is l. In a system ot air compressor control, a compressor, an air receiver, an air line leading from the compressor to said receiver, a check valve in said line,ran outlet to external atmosphere Vleading from the control side of said check valve, a normally closed atmospheric valve in Said outlet, a relatively small air line leading exteriorly from said receiver t to said last named valve for opening the same to unload the. compressor when the pressure in the receiver reaches a predetermined high point, and a motor switch controlled by variations in pressure in said relatively small air line to stop and start the motor. i Y

In a system of air compressor control, an air receiver, an. air line leading from the compressor to said receiver, a check valve in said line, an outlet to external atniosphere leading from the control side ofsaid check valve, a normally closed atmospheric valve in said outlet, a relatively small air line leading` 'from said receiver to said last named valve ttor opening the same to unload the compressor when the pressure in the receiver reaches a predetermined high point, a motor switch controlled by variations in Vpressure in said relatively small air line to stop and start the motor, and an exhaust valve in the relatively small air line actuated by the movement of said switch.

3. -In a system of air compressor control, a compressor, an air receiver, an air line leading trom the compressor to said receiver, a check valve in said line, an outlet to external atmosphere leading from the control side of said check valve, a. normally closed atmospheric valve in said outlet, a relatively small air line leading` from said receiver to said last named valve for opening the same to unload the compressor when the pressure in the receiver reaches a predetermined high point, a motor switch controlled by variations in pressure in said relatively small air line to stop and start the motor, and an exhaust valve in the relatively small air line actuatedy 1 by the movement of said switch, said extively small air line leading exteriorly from said receiver to said last named valve for opening the same to unload the compressor when the pressure in the receiver'reaehes :a predetermined high point, and a motor switch controlled by variations in pressure.

in said relatively small airline to stop start the motor.l

5. In a system of air compressor control, a

and

compressor, an air receiver, an air line leading from the compressor to said receiver, a check valve in said line, an outlet to external atmosphere leading from the control side ot said check valve, .a normally closed diaphragm operated valve in said outlet, a relatively small'air line leading from said receiver to said last named valve for opening the same to unload the compressor when the pressure in the receiver reaches arpredetermined high point, a motor switch controlled by variations in pressure insaid relatively small air line to stop and start theY motor, and an exhaust valve in the relatively small air' line actuated bythe movement of said switch.` f

G. In a system ot air compressor control, a compressor, an air receiver, an air line lead.- ing from the compressor to said receiver, a check valve in said line, an outlet to external atmosphere leading from the` control side ot' said check valve, a normally closed diaphragm operated valve in said outlet, a relativelyA small air line leading from said receiver to said last named valve for opening the same to unload the compressor when the pressure in the receiver reaches a predetermined high point, a motor switch controlled by variations in pressure in said relatively small air line .to stop and start the l,

motor, and an exhaust valve in the relatively small air line actuatedv by the movement of said switch, said exhaust valve arrangc-id to be actuated in one direction to open communication with the diaphragm operated mally closed diaphragm operated valve in said outlet, a relatively small air line leading exterior-ly from said receiverl to said last `named valve for Opening 'the saine to unload the compressor when the pressurein the receiver reaches a predetermined high point, and a motor switch controlled by variations in pressure in said relatively small air line to stop and start the motor.

8. In a system of air compressor control,

a compressor, an air receiver, an air line leading from the compressor to said receiver, a check .valve in said line, an outlet to eX- ternal atmosphere leading fromthe control side of said check valve, an adjustable norfl mally closed diaphragm operated valvein said outlet, a relatively small air line lead- 'ing from said receiver to said last namedy valve ffor opening-the same to unload the compressor When the pressure in the receiver reaches Vapredetermined high point, a motor switchcontrolled `by variations in pressure in said relatively small air line vto stop and start the motor, and an exhaust valve in the relatively small air line actuatedv by the movement of said switch.

9. In a system of air compressor control, a compressor, an air receiver,`an air line leading from the compressor to said receiver, a check valve in said line, an outlet to eX- ternal atmosphere leading from the control side of said check valve, an adjustable noimally closed diaphragm operated valve in said outlet, a relatively small air line leading from said receiver to said last named valve for opening the same to unload the compres,-

sor when the pressure in the receiver reaches a predetermined high point, a motor switch controlled by variations in pressure in said relatively small airline vto stop and start the motor, and an exhaust'valve inthe relatively smallv air line actuated by the movement of said switch, said exhaust valve arranged to be actuated in one direction to open communication With the diaphragm 'operated valve and in the other direction to connect the diaphragm operated valve With the external atmosphere.

l0. In a system of air compressor control, a compressor, an air receiver, an airline leading from the compressorito said receiver, a check valve in said line, an outlet to eX- ternal atmosphere leading from the control side of said check valve, a normally closed atmospheric valve in said outlet, a relatively smallA air line leadingv from said receiver to said last named valve for opening the same to unload the compressor when the pressure in. the receiver reaches a predetermined high point, a motor switch controlled vby variations in pressure in said relatively small air line to stop and start the motor, and a needle valve in the relatively small air line actuated by themovement oi'said switch.

1l. In a system of air compressor control,

a compressor, an air receiver, an airline leading from the compressor to said receiver, a check valve in saidline, an outlet to external atmosphereleading from the controlv side of said check valve, a 'normally closed atmospheric valve in said outlet, a relatively small air line leading from said receiver to said last named valve for opening the same to unload the compressor When the pressure in the receiver reaches a predetermined high point, a motor switch controlled by varia# tions in pressure in said relatively small air line to stop and start the motor, and a needle valve in the relatively small air line actuated by the movement oi' said switch, said needle valve arranged to be actuated in one direction to open communication With the atmospheric valve and in the other direction to connect the Vatmospheric valve with the external atmosphere.

In testimony, that we claim the fore 'oing as our joint invention, we have signerv our names this 22nd day of June, 1927.

FREDERICK Ag MLLER. LoRENTZ L. BAsBERe. 

